Portable electronic hemodynamic sensor systems

ABSTRACT

Systems and methods are provided for extracting hemodynamic information, optionally employing portable electronic devices with optional User Interface (UI) features for system implementation. The systems and methods may be employed for acquiring hemodynamic signals and associated electrophysiological data and/or analyzing the former or both in combination to yield useful physiological indicia or results. Such hardware and software is advantageously used for non-invasively monitoring cardiac health.

RELATED APPLICATIONS

This filing is a continuation application of U.S. patent applicationSer. No. 15/006,926, filed Jan. 26, 2016, which is a continuationapplication of U.S. patent application Ser. No. 14/601,170, filed Jan.20, 2015, now abandoned, which claims the benefit of and priority toU.S. Provisional Patent Application Ser. No. 61/929,880, filed Jan. 21,2014, Ser. No. 61/932,576, filed Jan. 28, 2014, Ser. No. 61/992,035,filed May 12, 2014, and Ser. No. 61/992,044, filed May 12, 2014, all ofwhich are incorporated by reference herein in their entireties and forall purposes.

FIELD

The present subject matter relates to devices and methods for obtainingand utilizing hemodynamic waveform measurements.

BACKGROUND

Cardiovascular diseases (CVDs) are the underlying cause of about one ofevery three deaths in United States each year. About 34% of Americanadults are suffering from one or more types of CVD. In 2010, the totaldirect and indirect cost of CVDs was approximately $503 billion.

There is an urgent need to develop new methods and devices fordiagnosing and monitoring CVDs. Diagnosis enables early intervention andremediation. Monitoring is a useful tool in behavior modification and inthe prediction and subsequent avoidance of acute events that can lead toemergency hospitalization, morbidity, and/or mortality. New methods anddevices to meet these need(s) advantageously enable extractinghemodynamic information from or in connection with a portable electronicdevice.

SUMMARY

Example embodiments of systems and methods are provided for acquiringand/or utilizing hemodynamic information, optionally, in connection withportable electronic devices. As such, a portable approach for thequantification of cardiovascular physiology and diagnosis ofcardiovascular disease (CVD) is provided that can operate utilizing amobile communication device (e.g., smartphone) platform. An optionalUser Interface (UI) and/or other features adapted for hemodynamic signalacquisition may be incorporated for system implementation.

In certain system embodiments, a smartphone, a hardware-modifiedsmartphone, a peripheral instrument or sensor(s) wired or wirelesslyconnected to a smartphone, or other portable electronic devices can beused to obtain physiological waveform data. Once a physiologicalwaveform has been acquired, the data can be stored locally or on aserver (e.g., the “Cloud”). The waveform may be analyzed remotely (e.g.,by or in the Cloud) or locally.

Certain calculations involving the waveform(s) may employ an IntrinsicFrequency (IF) method, a sparse time frequency representation (STFR)algorithm, or any other empirical mode decomposition based method. Otherapproaches are referenced below as well.

Various physiological parameters may be calculated from the obtainedphysiological waveform(s). In one embodiment, left ventricular EjectionFraction (EF) can be calculated and displayed to the user. In anotherembodiment, Stroke Volume (SV) and/or Cardiac Output (CO) can becalculated. For either such determination, see U.S. patent applicationSer. No. 14/517,702, filed Oct. 17, 2014, and titled, “INTRINSICFREQUENCY ANALYSIS FOR LEFT VENTRICLE EJECTION FRACTION OR STROKE VOLUMEDETERMINATION,” incorporated by reference herein in its entirety and forall purposes. Another approach to determining EF may be adapted from“The Relationship of Alteration in Systolic Timer Intervals to theEjection Fraction in Patients with Cardiac Disease,” Circulation. 1970;42: 455-462 with related systolic time intervals determined by referenceto “Systolic Time Intervals in Heart Failure in Man,” Circulation. 1968;37:149-159 and “The Relationship of Alterations in Systolic TimeIntervals to Ejection Fraction in Patients with Cardiac Disease,”Circulation. 1970; 42: 455-462, both of which are incorporated byreference herein in their entirety for all purposes. In yet anotherexample embodiment, IF values (ω₁, ω₂) are calculated and a healthstatus determination can be displayed. For such determinations, see U.S.Patent Publication No. 2013/0184573, also incorporated by referenceherein in its entirety for all purposes.

The embodiments described herein can obtain electrocardiogram (i.e., EKGor ECG), phonocardiogram, and arterial pulse waveforms. Theseembodiments can include an optical sensor for the measurement of thearterial pulse waveform and/or heart sound. Optical detection may beaccomplished by a LED or photodiode combination. In another embodiment,a pulse wave may be recorded via microwaves. A microwave transceiver maybe located behind the screen of the mobile communication device for suchpurpose.

Regarding specific hardware implementations, one example embodimentinvolves quantification of cardiovascular physiology and diagnosis ofCVD utilizing a standard smartphone platform (typically in connectionwith customized hardware and/or software). These embodiments exploit theanalog signal from a camera in combination with the camera LED flash tomeasure the reflectance of light off the skin in the proximity of anartery passing near the surface of the skin to quantify its radialexpansion in response to a time varying blood pressure. Such an approachoptionally involves a series of components: using a camera integrated ina portable electronic device to record the motion of the skin to capturethe shape of the blood pressure waveform, user feedback provided throughvisual and/or auditory signal(s) enabling the enhancement of signalquality, and the design of the data display and analysis. Although theapproach is described herein in terms of cardiovascular waveforms, avariety of waveforms can be analyzed employing such a platform.

In certain embodiments where such systems are used, a user locates apulse where a major arterial passes near the surface of the skin andplaces the phone such that the camera and LED both image and illuminatethe location respectively. A prepare screen then begins to display therelative motion of the skin. In one embodiment, the average intensity ofthe camera signal is used to create a signal describing the relativemotion of an artery. In another embodiment, only particular regions ofthe camera image are subjected to averaging, although more elaborateimage processing schemes are possible for such information as known bythose skilled in the art that may be applied hereto. In addition, thedevice's LED intensity may be adjusted to maintain an adequatesignal-to-noise ratio for the waveforms being acquired by the device.The LED may also be strobed in a manner that cuts down on noise (e.g.,by offsetting from or screening out other frequencies where noise ispresent). For example, the LED can be pulsed at a frequency above whatcommon electronics use. In some embodiments, the LED strobing frequencymay be between 500 Hz and 1 GHz or more preferably in the range of 2 kHzto 64 kHz.

In another embodiment, the waveform may be obtained through a peripheralinstrument such as a wired pulse oximeter. Indeed, the waveform may beacquired through any of microwave, strain-gauge, piezoresistive,capacitive, optical, or acoustic sensors. A combination or multiplexingof sensors may be used. For example, an array of LEDs and detectorscamera or photodetectors may be used to analyze the motion of the skinssurface. In one embodiment the detector is a phototransistor. In anotherembodiment, the detector is a photodiode. Such instruments may beconnected through a microphone jack to a/the smartphone. In someembodiments, the peripheral instruments are connected wirelessly such asthrough WiFi or BLUETOOTH.

To accommodate different body types, a probe-style peripheral sensor(e.g., in a stethoscope-type shape) with a detector and an array of LEDsmay be used. Such a probe may also be adapted to perform an ECG. Theprobe may include one or more ECG sensor contacts leads or electrodes onthe probe head for such purposes. In another embodiment, the probe hasone or more ECG electrodes on the probe head and at least one additionalelectrode on a grip portion, thereby providing an increased measurementpath if the device is held in position by the user. In anotherembodiment, the probe has a secondary connection to add an additionalECG electrode for the case where an operator is holding the device forthe subject. In this case, the grip portion ECG electrode is optionallydeactivated.

The above offers an example of a so-called “multiplexing sensor.”Another embodiment includes a waveform detecting sensor, ECG electrodesand a microphone combined into a peripheral data probe. This or anotherprobe may also measure blood pressure, hydration, skin impedance,temperature, the waveform as well as a phonocardiogram.

In another embodiment, the sensor device is enclosed in a specializedcase to enhance waveform acquisition (e.g., as in the example ofsmartphone hardware). This case may integrate a multitude of sensors.The case may include optical components such as lenses allowing thelocation and direction of the incoming optical signal to be adjustedaccording to body type and skin rigidity. Case hardware may also beprovided to set a standoff distance for the device camera and LED thatare adjustable between about 10 μm to about 10 cm. A mechanical add-onto the device case (or directly to the smartphone) may be provided toenable relative positioning and/or tensioning of the skin.

In one example of skin tensioning hardware, a ring with variousdeflectable, deformable and/or stop features as detailed below may beemployed. In another example, a sensor membrane may be provided in the(optical) sensor system. The membrane may comprise any number ofplastics, animal skin, and/or rubber. A polyester or polyurethanemembrane may be preferred.

Whether employed in connection with skin-tensioning hardwareconfigurations or adaptations or merely as a sensor interface in use,the membrane is located or placed in contact with the skin where signalacquisition is desired (i.e., between the optical sensor and the skin).The thickness of the membrane and material from which it constructed(e.g., rubber, plastic, metal or composite material) is chosen toexhibit mechanical properties that allow the membrane to follow theunderlying pulse waveform and record the same. As such, the membrane mayhave a thickness is in the range of about 12 to about 500 μm. Themembrane may cover a diameter ranging from 1 mm to 50 mm. The opticalproperties of the membrane may be chosen such that it reflects at thewavelengths of the LED incorporated in the smartphone (or used in aseparate device) and ambient light to otherwise decrease signal noise.It may be optically opaque at the wavelength or wavelengths ofdetection.

Indeed, the membrane serves a number of functions such as normalizingfor subjects skin tone, acoustic coupling for phonocardiographicmeasurements as well as providing a sterile and disposable barrier fortesting. In another embodiment, the membrane is not disposable.

When the membrane is disposable it may snap, press-fit, or screw inplace. In another embodiment, the membrane is housed in anothercomponent that couples it to the handheld sensor device. The membranemay have a rigid frame. Use of such a membrane incorporated in ahemodynamic sensor device (as in a device for direct attachment to asmartphone and/or as incorporated in a stand-alone sensor embodiment)serves the purpose of increased robustness to user skin tone and bodytopography. As to further details of its operation of the membrane foruse in pressure waveform monitoring in connection with a light source(be it an LED, laser or otherwise), these can be appreciated inreference to U.S. Pat. No. 5,363,855 incorporated herein by reference inits entirety for all purposes.

The membrane may have multiple regions with different or varyingmaterial properties. In another embodiment, additional constraints orstructures may be used to enhance signal quality. In another embodiment,the device may not have a membrane.

In addition to picking up a pulse waveform from skin vibration caused byunderlying arterial motion, the subject membrane-based sensorarrangement (including a light source and sensor for light reflectedfrom the membrane) is able to detect a higher frequency range ofvibrations corresponding to the so-called heart sounds. Notably, thesesounds are offset in timing from heart sounds that can be detected overa subject's heart (i.e., in the region of the sternum).

The nature of heart sounds that may be detected at a peripherallocations were the subject of some study roughly half-a-century prior tothe subject filing. Particularly, Farber et al., in “Conduction ofCardiovascular Sound Along Arteries,” Circ. Res. 1963; 12:308-316,discussed the origin of heart sounds that may be detected at aperipheral location as well as their mode of propagation. The inventorshereof believe that those authors properly concluded that the heartsounds that may be detected at peripheral location(s) ride upon or areembedded with the blood pressure wave. Embodiments provided herein applysuch information to practical use for complex calculation ofphysiological parameters.

In these embodiments, the heart sounds that are generated (i.e.,resolved or separated as further discussed below) from the vibrationsignals obtained are referred to herein as Embedded Frequency signals orEmbedded Frequencies. The heart sounds may be acquired optically andisolated by amplifying and filtering. The heard sounds may be isolatedby high pass filtering the pulse waveform. The filtering may be achievedby mechanical filtering or by the response bandwidth of a transducer asin the case of a microphone.

As detailed further below, the properties and timing (especially itssynchronicity relative to the pulse waveform) of the Embedded Frequencysignals offers great utility in interpreting the features of the pulsepressure waveform and other possible utility heretofore unused and/orproblematic to otherwise derive.

Additional embodiments hereof include various improved techniques forsignal acquisition. These techniques may be integrated into the UI ofthe subject devices and/or accomplished through interaction with aperipheral marker, beacon or service. Any of these various audio and/orvisual indicators discussed below may be regarded as various selectablesignaling means.

In one set of examples, an auditory signal is assigned the informationstreaming from the camera in the sensor device platform. For example,each camera frame may be averaged and turned into a single instantaneouspoint, therefore a frame rate of 30 fps produces a (background auditory)signal of 30 Hz. In another embodiment, the camera or sensor acquisitionrate ranges from 10 Hz to 100 kHz. In another embodiment, the auditorysignal is produced by multiplying or modulating a background auditorysignal such as white noise by the incoming data. In another embodiment,the time derivative of the incoming data is multiplied by a backgroundauditory signal. In another embodiment, the incoming data is manipulatedthrough a mathematical operator. In another embodiment, the backgroundsignal is brown noise, pink noise or of a single frequency. In anotherembodiment, the background sound is user customizable. In sum, the exactdetails or feel of the background auditory signal modulated by thephysiological waveform data is left up to those skilled in the art.Nevertheless, the sound (i.e., background auditory signal) may berescaled to still be audible for weak signals. The auditory cutoff forthis sound may be used to indicate a minimum threshold for a usablesignal.

In another set of examples for optimizing signal acquisition location,the user is prompted visually or audibly to move locations until thesignal possesses a particular quality or span. This sound may have therecognizable character of a phonocardiogram. Such an auditory feedbacksignal may be used to allow the user to home in on the optimal locationbased on (audibly detected) waveform shape and intensity. Alternatively,the auditory feedback may take the form of a beep or similar noise. Thefrequency of beeping may increase as sensor device position is improvedby the user to improve acquired signal quality. Once achieved, aposition “lock” may be indicated by a constant tone.

In another embodiment, acquisition signal quality is indicated by anindicator light. This indicator may be an icon on the screen of a/thesmartphone and/or peripheral device. Alternatively, the visual signalmay take the form of a slide or meter. Such a meter may comprise aseries of collinear dots or the meter may rotate like a clock orspeedometer. Another such meter may comprise a target or series ofconcentric rings which are illuminated towards the center and/or flashin a similar pattern.

In another embodiment, signal quality indices are applied to screen theincoming physiological waveforms. These signal quality indices may bebased on the timing, span, or shape of the waveform or combinationsthereof. These indices may be used to communicate with the user toprompt improved positioning, retaking of data or other (re)action.Likewise, machine learning or neural network type algorithms may beutilized to screen poor waveforms and/or alert the user to properlyacquired physiological waveform data.

In another embodiment, a locator system may be provided in connectionwith a physical marker or external device which has communicated or isin communication with the waveform acquisition system. Conventionalpositional triangulation techniques and RF or other signaling may beused for such purposes. In another embodiment, a directional microphonetargeted to the location of maximum sensitivity of the camera may beused to detect the optimum location/position. In another embodiment, afocused LED or low power laser is used to roughly indicate the center ofthe sensor area to the user.

In yet another embodiment, locating the sensor device for optimal signalacquisition may be achieved in connection with a constant markerpreferably not (although possibly) seen by the user. Such a marker maycomprise an IR skin tag or IR tattoo viewable only to the camera andilluminated via the LED. In one embodiment, these are alignment marksindicating position as well as orientation. As another alternative, aninjectable skin tag in the form of a small metallic or ferromagneticcomponent may be used. The injectable skin tag may comprise an RFID chipor other small electronic device.

More generally, embodiments hereof include systems (including the sensorhardware referenced herein and the addition of a computer processor andother ancillary/support electronics and various housing elements),methods (including software and associated hardware for carrying outspecified acts) and UI features (including layouts and options and/ormethodology associated with system use). Many of the subject deviceand/or system embodiments may be adapted for wearable as well ashand-held use.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures provided herein may be diagrammatic and not necessarilydrawn to scale, with some components and features exaggerated and/orabstracted for clarity. Variations from the embodiments pictured arecontemplated. Accordingly, depiction of aspects and elements in thefigures are not intended to limit the scope of the claims, except whensuch intent is explicitly stated.

FIGS. 1A and 1B are diagrams illustrating dynamic coupling of the heartand aorta in a human circulatory system.

FIG. 2 is a cutaway anatomical illustration showing device positioningfor signal acquisition.

FIG. 3 is a system overview including exemplary hardware of oneembodiment.

FIGS. 4A and 4B are opposite face-side views of smartphone hardwareemployed in another embodiment.

FIGS. 5A and 5B are opposite-facing oblique views of a specializedsmartphone case hardware and associated hardware that may be employed inanother embodiment.

FIG. 6 is a cross-section view including optional skin-tensioning andsignal-amplification hardware.

FIGS. 7A and 7B are cross-section views illustrating use of one of theskin-tensioning variation in connection with the embodiment illustratedin FIGS. 5A and 5B.

FIGS. 8A-8C are cross-section views illustrating use of another of theskin-tensioning variation that includes a sensor membrane.

FIG. 9 is a diagram illustrating optical properties of a selected sensormembrane.

FIGS. 10A and 10B are schematics illustrating electronics of opticalacquisition embodiments.

FIGS. 11A and 11B are diagrams of the anatomy interrogated forhemodynamic signal acquisition.

FIG. 12 is a chart showing optically acquired hemodynamic data.

FIGS. 13A-13C are charts variously illustrating Embedded Frequencymeasurement and methodology.

FIGS. 14A-14C are flowcharts illustrating various sampling localizationoptimization approaches.

DETAILED DESCRIPTION

Various example embodiments are described below. Reference is made tothese examples in a non-limiting sense. They are provided to illustratemore broadly applicable aspects of inventive aspects. Various changesmay be made to the embodiments described and equivalents may besubstituted without departing from their true spirit and scope. Inaddition, many modifications may be made to adapt a particularsituation, material, composition of matter, process, process act(s) orstep(s) to the objective(s), spirit or scope of the claims made herein.

As pertinent to certain measurement and calculations performed inconnection with the subject systems, pressure and flow waves generatedby the heart propagate in the compliant arterial vasculature. Thesewaves are reflected at various reflection sites in the arterial system.The waves carry information about the heart, vascular system andcoupling of heart and vasculature. As a result, extracting informationfrom these waves is of great importance.

FIG. 1A illustrates a coupled heart-aorta system 10 in systole, with theaortic valve open (not shown) and blood being pumped by the heart 12into the aorta 14. The heart and aorta construct a coupled dynamicsystem before the closure of the aortic valve. As shown in FIG. 1B,after aortic valve closure during diastole, the heart and aorta systemsare decoupled in a second system state 10′. The aortic waves contain ineach state include information about heart dynamics, arterial networkdynamic and heart-aorta coupling. Extraction of such information byanalysis enables a variety of determinations concerning cardiovascularhealth and/or various parameters as further discussed herein. Thesubject technologies are of use on obtaining hemodynamic wave formsignals for such analysis and other analysis as may be desired.

As summarized above, various hardware, methodology or software and UIfeatures (collectively, “technologies”) are contemplated for theacquisition of hemodynamic waveform data. One set of these technologiesinvolves sensor device configurations and/or processing for signalacquisition. Another set involves signal sampling location optimizationtechnologies. Some of these technologies involve marking and/or locatingtechniques, the latter including UI-type feedback techniques. After thephysiological data has been acquired and analyzed, it may variouslyyield indication or display (i.e., on the subject portable electronicdevice) instantaneous health status, heart ejection fraction, strokevolume and/or cardiac output.

Handheld Sensor Devices and Systems

FIG. 2 provides a view of a human user or subject 20 with a cutawayillustrating various anatomical features along with a handheld sensordevice 100 targeting the common carotid artery 22, optionally around thecarotid bifurcation 24 for hemodynamic waveform acquisition. For thispurpose, a base 102 of the device may be separated from the skin by somedistance. In one example, this “standoff” distance is about 1 mm.Although not shown, device 100 may be held by the subject 20 or anotheruser employing handle interface 104.

This handheld sensor unit or device 100 may include an ECG electrode 110associated with the handle (e.g., as discussed below). Signalacquisition status, prompts and/or other programming signals orinstructions may be transmitted between handheld device 100 and othersystem components (as further described below or otherwise) via RFenergy 120 in the form of WiFi, a BLUETOOTH signal or using anotherprotocol.

As referenced further below, various UI features may be incorporated inthe subject system(s). An associated element may be in the form of amarker affixed (as in a tattoo) or implanted (as in a biocompatiblepellet or more complex device) at an optimal spot for signal acquisitionas indicated by the asterisk (“*”) in FIG. 2. Such a feature may simplyindicate a target point. Alternatively, the marker feature may include adirectional component for rotational registration. Such an approach maybe implemented employing a rod, diamond-shaped or box-shaped marker bodyor indicator and/or a selected pattern applied to or implanted withinthe subject's skin. FIG. 3 describes an overall system 300 including ahandheld sensor device 100, a smartphone unit 200 and an optionalcharger and/or sterilization unit 210 for device 100. As illustrated,smartphone 200 communicates with/between sensor device 100 employingsignals 120/220 as in “paired” BLUETOOTH devices or via anotherprotocol. The smartphone may receive information corresponding to ahemodynamic signal as further treated below. Such a signal may be storedand/or processed via connection with the Internet—as in so-called Cloud202 computing.

Regarding further optional features of the handheld sensor device 100,its perspective view included in FIG. 3 yields additional details.Specifically, a face or facing surface 106 of base 102 incorporatesadditional sensors. These may include an ECG electrode 110′, an opticalsensor or sensor region 112 and/or microphone(s) 114. Optional use oftwo microphones allows for direction sound sensing for homing in on animproved or ideal signal sensing location. As another option, a plug orport 116 may be provided for connection to yet another ECG electrode110″ (for when the device is not held or operated by the user) or otherperipheral hardware (e.g., head phones for the audio signal of acardiophonogram (i.e., for auscultation). The handheld device 100 may beplaced in a wireless charging station 210 for recharge. A UVsterilization system may be included with the wireless charger. Inanother embodiment, device 100 and its components (e.g., including asensor membrane as discussed further below) may comprise materialscompatible with ethanol sterilization.

FIGS. 4A and 4B illustrate an approach in which the smartphone itself isused as the sensor means in a combined sensing and processing device310. Various other peripheral components may be attached thereto aswell. A direction microphone 312 may be so-connected. Or such amicrophone 312 may complement a built-in microphone 314 to providedirection sound sensing.

In any case, the smartphone platform will typically include a camerasensor 316 and one or more LED light or “flash” element(s) 318. Or onesuch element may be a focused LED or low power laser used to roughlyindicate the center of the sensor area to the user. In any case, withthe camera and incorporated lighting system(s), the device is able tosense and capture a hemodynamic waveform. Such information may befurther processed and depicted as shown in FIG. 4B on screen or display320 and further commented on below.

Device 310 may be received (as indicated by dashed line) within a case330 such as shown in FIGS. 5A and 5B. Features of such a case mayinclude an adjustable standoff feature and/or an amplification ringstructure 400. This structure may include screw-in, twist-and-lock orsnap attachment features 402 to secure the amplification ring to thedevice or device case. The ring may also include optics to furtherenhance the detection qualities of the smartphone. Around a window oraperture 340 for camera or sensor optics, case 330 may includeamplification sub-system interface features 342 complementary tofeatures 402.

As a body 332 of the case will typically be adapted for a given model ofsmartphone, its camera aperture 340 and a flash or LED aperture 334,volume and/or lock interfaces or clearances 336 and various connectorthrough holes 338 will be so-configured. This body (and/or itsconstituent parts) may comprise plastic or any other conventionally usedsmartphone case material.

FIG. 6 details further optional aspects of the so-called amplificationring 400. Note, however, that this system element need not be “ring”shaped. In one embodiment (i.e., as shown), the structure is a hollowcylinder. In another embodiment, the structure is not a cylindrical buttwo barriers. In another embodiment, the structure is square in shape.While any number of geometries are possible depending on the region ofinterest and physiological signal, the exact geometry of the structureis left up to those skilled in the art.

In any case, FIG. 6 discloses hardware and a method for tensioning amaterial surface and/or underlying tissue or material to amplify motionas a wave is transferred from one medium to another. This method can beapplied to tension the skin to increase the sensitivity of noninvasivephysiological measurements. Generally, this method involves placing astructure 400 on top of the skin 40 of a subject with an artery 42passing beneath. The structure channels the energy of a physiologicalsignal 50—in this case pressure waveforms as function p(x,t) generatedby the dynamics of the heart and arterial tree—within a region ofinterest “ROI”. As such, an amplified waveform 52—as compared to lesseramplitude waveform 54 outside structure 400—may be captured.

Structure 400 may also include accessories or modifications to enhanceperformance as well as increase comfort. In one embodiment, the cylinderhas a rounded edge 404. In another embodiment, the structure has asilicone or soft rubber bumper 406 at its distal interface (i.e.,positioned as indicated for element 404). This bumper is able to deformto further tension skin. In another embodiment, the bumper is in theform of an O-ring 408. In another embodiment, the bumper iscross-sectionally formed to include a hinge 410 utilizing lever or rim412 action to increase tension on the skin.

FIGS. 7A and 7B further illustrate this last variation. Here, hingingand lever action is accomplished as evident comparing the views once therim or lever sections 412 are in contact with a subject's skin 40. Asshown in FIG. 7B, the system is intended to measure movement ormicro-movement (as indicated by the double-arrow) of the skin set withinor surrounded by the ROI. A complementary threaded interface 342/402 isalso shown securing a body 420 of the amplification ring to a/thesmartphone case body 332. Alternatively, such an interface may beincorporated into a smartphone or another device. Amplificationstructure 400 may include lens and/or filter elements 422 for anassociated device sensor 316 (be it a CMOS or CCD- or other lightsensor) and LED 318 (or other light source) in an overall system 300.

In another amplification structure 400′ embodiment, concentric cylindersare used to provide tensioning and amplification. FIGS. 8A-8C illustratesuch an approach. Here, structure 400 included concentric rings 430,432. These rings may be included in the body or base 102 of an auxiliarysensor device, a body 320 of a smartphone device or the body 420 of anadd-on amplifier structure like that in the preceding figures.Regardless, the interaction between a subject's skin 40 and the innerand outer rings 430, 432 stretch the skin as shown in FIGS. 8B and 8C.

In FIG. 8B, initial contact with made with the skin along the outer ring432. Then, in pressing the structure 400′ as indicated by the largerarrow, contact is achieved at/around the inner ring 430 stretching theskin and/or a membrane 440 interface incorporated in the structure.

Use of a membrane 440 as in the above embodiment enables furtherlight-selective methodologies. Optical properties of the membrane areadvantageously chosen such that it reflects at the wavelength of the LEDback to the device sensor as well as blocks noise caused by ambientlight. These results may be achieved by coloring and/or metalizing apolymer membrane (inside and/or out) via Chemical Vapor Deposition (CVD)or otherwise. Additionally, the membrane serves the purpose of increasedrobustness to user skin tone and body topography.

These concepts are illustrated in connection with FIG. 9. Here, exteriorambient light 442 from any source is reflected. It may also be desirablethat light from an internal source (such as a/the LED 418) pass itsvisible (Vis) spectrum component(s) through membrane 440 and onlyreflect its Infrared (IR) component to a/the sensor. Such an approachcan help reduce signal nose.

Most important is that external light does not pass through the membraneto the interior of the device where the sensor(s) are located. As such,the metalized surface may desirably set to the outside of the devicewhere it reflects ambient light out or outward. As such, such anarrangement keeps all the internal light inside the device.

Whether incorporated in an amplification “ring” structure 400/400′ orsimply set in or across a sensor aperture or window 340 a/the membrane440 may comprise any number of materials such as metals, plastics,animal skin and/or rubber. It advantageously comprises polyester orpolyurethane. Physical parameters of the membrane are chosen to exhibitmechanical properties which allow the membrane to follow the pulsewaveform. As such, membrane thickness is typically in the range of12-500 μm with a diameter ranging from 1 mm to 50 mm.

As variously discussed, one application of the hardware and subjectmethodology is for arterial waveform measurement. In this regard, theamplified motion of the skin correlates to the pressure driven expansionof an artery. The amplified motion can therefore subsequently berecorded through any number of non-invasive transducers such aspiezoelectric, capacitive, piezoresistive, optical, acoustic, ultrasoundor electromagnetic. Similar techniques may be applied to measurephysiological wave information that exists at different frequencies suchas arterial waves versus phonocardiograms. The signal can be recordedusing an optical reflective light sensor (e.g., with sensor 112 or 316).In another embodiment, a combination or array of these structures may beused to probe local arterial mechanical properties.

In the embodiment noted above, the amplification structure is housed ina mobile phone case or employed as a (direct) mobile phone attachment.In another embodiment, such a structure 400/400′ could be built directlyinto the body or housing of the phone. In another embodiment, thestructure is placed in a peripheral and/or portable device.

In any case, system componentry for optical embodiments for hemodynamicwaveform acquisition are shown in FIGS. 10A and 10B. These systems 500(as may be incorporated in those above) include an LED driver infunctional block 502. A functional block 504A in FIG. 10A for thediode/LED includes each of Low Pass (LP) filter, a High Pass (HP) filterand an Amplifier. A functional block 504B in FIG. 10B, again, for thediode/LED includes each of a band bass (BP) and low pass (LP) filter andAmplifier. Via an analog-to-digital (A/D) converter 506, the signalcaptured may be passed by a communication block 508 (e.g., throughBLUETOOTH protocol) to a computer or handheld device 200 display orother electronic hardware for processing as variously described herein.

As to the different filtering options (i.e., differences apparentbetween blocks 504A and 504B), note that the HP filter in FIG. 10A issubstituted for the BP filter in FIG. 10B. A BP filter may be used incase of a large DC offset present in the signal. However, an AC signalmay be used, coupled with a LP filter. AC coupling is loosely analogousto a very low frequency HP filter. In which case, the figures may beviewed as analogous. All of the filtering may also all be donedigitally. Stated otherwise, the filtering and DC offset removal can bedone in the digital or analog domain. Likewise, DC offset removal, HPfiltering, LP filtering and amplification can be done in parallel or inseries.

Referring to FIGS. 11A and 11B, these figures show a blood vessel 42 andskin section 40. Radial distension from blood pressure is pictured invessel 42 in FIG. 11A, and up-and-down movement of the skin 40 in theside view of FIG. 1B.

Representative data optically captured from such movement is shown as bydata points 60 in FIG. 12 generating a 600 hemodynamic waveform. As thisdata may be variously smoothed and processed into a discrete curve (asshown in other views herein), with a first section or a firstsection/domain 602 in which the heart and aorta are in a coupled system10 and a second section/domain 604 for the aorta in a system 10′ aloneas in FIGS. 1A and 1B. These domains are delineated (or separated) bythe Dicrotic Notch (DN) as shown.

Pulse Waveform and Embedded Frequency Acquisition

Using the subject hardware, a second set of frequencies correspondingwith the heart sounds (the “Embedded Frequencies”) are embedded withinan arterial blood pressure waveform. As such, two different types ofwaveform can be obtained from the same location using the same device.Currently, tonometers for measuring blood pressure waveforms based onpressure sensors cannot or do not detect the Embedded Frequencies. Also,known stethoscopes (digital or otherwise) can detect heart sound, butthey cannot or do not detect arterial blood pressure waveforms. Thissituation may be due to low-pass and high-pass filtering employed in thedevices as a matter of course or design.

In any case, embodiments of the subject hardware and/or software discardneither signal. Rather, a vibrational signal on the skin of a patient isobtained and the signal is resolved in into each of a pulse pressurewaveform and an Embedded Frequency signal. Doing so makes a number oftechniques practical in application, even for a patient toself-administer.

As shown in FIG. 13A, each of a hemodynamic waveform (i.e., pulsepressure waveform) 610 and an Embedded Frequency waveform 612 have beendetected and resolved into discrete signals.

Although other filters may be used, such resolution is preferablyachieved by high-pass and/or low-pass filtering using Fouriertransforms. Low-pass filtering yields the true pulse pressure waveform.High-pass filtering yields the true Embedded Frequency (or heart sound).Current filtering is set with High-pass about 20 Hz and Low-pass atabout 250 Hz.

In some examples, a second derivative may be taken of the vibrationalsignal for this purpose. However, Fourier transform filtering maygenerally be preferred as a more accurate form of filtering. Whereas asecond derivative will tend to amplify noise, a filter can cut it back,thus providing more accurate “character” of a sound. In other words, useof a classical filter (such as one based on Fourier transform) may beadvantageous because it does not artificially amplify higher frequenciesthereby making it easier to analyze a high pass signal—the EmbeddedFrequency in this case.

Signals 610 and 612 were captured together as one vibration signaldetected with an optical sensor embodiment including a membrane asdiscussed above. This example was generated from measurements taken atthe carotid artery (e.g., a pictured in FIG. 2) although other locationsperipheral to the heart (e.g., femoral or radial) would yield similarresults.

The Embedded Frequency signals present at least three properties. Theproperties open-up various opportunities of interest.

First, it has been observed that the Embedded Frequencies maintain thesignature of the heart sound (i.e., they have the same profile orcharacteristics as sound waves originating at the heart). Accordingly,the signals can be used for cardiac auscultation.

Second, the Embedded Frequency signals maintain a constant distance fromthe beginning of the arterial blood pressure waveform to its DicroticNotch (DN). In contrast, sound waves measured at the heart travelthroughout the body instantaneously making it difficult to use heartsounds to approximate the opening and closing of the aortic valverelative to a pressure waveform measurement (because the pressurewaveform is offset from the instantaneous heart sound at peripherallocations). But because the Embedded Frequency signals travels with thearterial blood pressure waveform, they keep a unique synchronicity ortiming property with the arterial blood pressure waveform allowing foreasy detection of the DN. As such, the closing of the aortic valve(i.e., setting the location of the DN as indicated in FIG. 13A) canpossibly be resolved even with a nondescript hemodynamic signal 620 asshown in FIG. 13B. This can be of great benefit, especially inaccurately parsing a hemodynamic pulse pressure signal 600 into itsconstituent parts 602 and 604 on either side of the DN for IF analysis.Indeed, any cardiac cycle detection and/or segmentation of heartwaveforms is potentially aided by the use of Embedded Frequencies. Ingeneral, timing related to arterial blood pressure waveforms can now beaccomplished using the Embedded Frequencies instead of or in combinationwith arterial blood pressure waveforms.

Third, the travel time of the Embedded Frequencies with the pulsepressure waveform enables simplified methods of determining Pulse WaveVelocity (PWV) and/or Systolic Time Interval (STI) as elaborated in theExamples below.

Generally, the subject hardware and associated Embedded Frequencymethodology opens opportunities for physiological/hemodynamiccalculation and property quantification. The ability to capture bothhemodynamic waveform and Embedded Frequency signal while eliminating theneed of separate tonometer and stethoscope hardware and/or sensinglocations offers various advantages. Moreover, the incorporation ofmulti-sensor technology (e.g., by including various ECG signalacquisition options in the sensing device or system) provides furthersynergy and opportunities.

Sampling Location Optimization

As referenced above, sensor location is important for good signalacquisition. Accordingly, a number of techniques for identifying optimalsensor location are provided. FIGS. 14A-14C illustrate various examplesof methods (optionally, medical methods) and software routines ortechniques. As noted, these techniques may be integrated into the UI ofthe subject devices and/or accomplished through interaction with aperipheral marker, beacon or service.

In one set of UI embodiments noted above, auditory and or visualsignal(s) for a user are assigned to information streaming from a/thecamera in the sensor device platform. As shown in FIG. 14A in moregeneral terms, a hemodynamic signal is sensed at 700. This signal ismodified or manipulated at 702 in any of various ways possibly describedabove or others, then output as a user identified or identifiable signalat 704. Such signaling may be auditory (e.g., as in from resolution toan intelligible signal out of noise, as from nothing to hearing asignal, as in an accelerated beeping to achieve a “lock,” etc.) orvisual (e.g., as indicated by light blinking or intensity, as gauged bya meter, etc.) as described above or otherwise. As the user moves thesensor device the process continues as indicated by the loop line untilthe user is directed by device feedback to a location where adequatesignal is obtained and the process ends at 706.

In another set of UI embodiments, a method may be carried out inconnection with a locator system as illustrated in FIG. 14B. In whichcase, sensing may begin at one position at 700. Using directionalmicrophones or other techniques, this position can be related to moreoptimal position at 708 and then the user directed accordingly (such asby above or otherwise) at 704 as he or she moves towards or away from amore optimal position for sensing. As indicated, repeated signaling andsensing may be required. When an adequate signal is sensed and recorded,the process may end at 706.

In yet another set of UI embodiments, locating the sensor device foroptimal signal acquisition may be achieved in connection with a constantmarker as illustrated in FIG. 14C. In which case, the system mayidentify the marker (i.e., not usually viable to the user as discussedabove) at 710. Then via various user-identified signal options (perabove or otherwise) direct the user to the marker location at 712. Uponachieving desired location, sensing may then occur at 700 after whichthe process ends at 706. If optimal placement has not been achieved,however, or if multiple nearby sampling points are desired then themethod may be run repeatedly or recursively with either goal in mind(i.e., for more accurate home-in to the marker and/or scattered samplingadjacent the marker point).

Examples

The subject systems have been discussed above as capable of deliveringhemodynamic waveform data optically by acquisition with a smartphone inconnection with its LED flash element and an LED phototransistor pair.Such data may be smoothed or averaged in connection with a graphical UI.

With reference to FIG. 4B, a carotid pressure waveform 800 is shown asrecorded using an IPHONE camera and LED per above (although FIGS. 4A and4B illustrate another smartphone hardware option). On display 320, acomplete cardiac cycle 802 has been marked by three colored circularmarkers in the following sequence: red 804, white 806 and blue 808(whereas this particular color scheme was created to cause the user toinfer a particular—familiar—order as red being first, white second andblue third.) In this case, the time duration between the red and bluemarkers is the period of the cardiac cycle.

Display 320 also shows a Heart Rate (HR) of 60.03 bpm and ω₁=100 andω₂=50.4 calculated using a/the Cloud 210 computing service. Thenutilizing the approach described in U.S. patent application Ser. No.14/517,702, ejection fraction for the exemplary measurements wasproduced yielding a result of 68%. This result offered good agreementwith an ejection fraction of 64% for the same patient as measured by abiplane echo. In another example, ω₁ and ω₂, were calculated (also usinga/the Cloud service) as 93.63 and 29.6, respectively, with a HR of 94.84as shown in FIG. 3.

In each example (but described further in reference to FIG. 4B), theindividual color-coded points in the waveform(s) can be selected using acombination of the markers and the “plus” and “minus” buttons 810. Inone embodiment, a finger tap selection on the graph frame displaying thewaveform auto-locates the markers based on the marker selected and thelocation of the tap relative to the graph frame. In another embodiment,the points are advanced into position using a slider. In anotherembodiment, the markers on the waveform can be dragged from sample tosample. In yet another embodiment, gestures or voice commands may beused to increment the markers in either direction. The markers can bestepped through the points on the waveform my clicking the plus andminus buttons. This sequence corresponds to the start, Dicrotic Notch(DN) as well as the end of a complete cardiac cycle and are the threeinputs in addition to the data required by the intrinsic frequencyalgorithm.

These features are important to delivering a feel of control to the usergiven limited screen size of portable devices and the size of a fingeror handheld stylus, particularly when high sampling rates are used.Since picking the points can affect the diagnostic outcome this UIcontrol is a required feature. Additionally, this UI feature allows abalance between accurate point selection of the cardiac cycle whileallowing the user a visual reference to larger features of the waveform.Also, the ability to manually confirm or select points can avoid anyautomatic selection that errors in selecting the DN, which can bedifficult with previously known techniques.

However, an example herein provides a reliable means of determining theDN position or location within the subject hemodynamic waveform data.Namely, with data acquired from systems capable of detecting and/orfiltering for an Embedded Frequency signal, as seen in FIG. 13A, it hasbeen observed that the portion Embedded Frequency 612 created during theclosing of the aortic valve remains a time interval (“t”) approximately40 milliseconds behind the Dicrotic Notch (DN) of the blood pressurewaveform 610. In practice, the exact amount of delay or the exactfeature of the S2 that we look at depends on the filter itself.Generally, there is a delay (e.g., about 4 to about 40 milliseconds)behind the notch. This slight delay will be dependent (but consistent)on the filter qualities. As such, the Embedded Frequency provides acomputationally efficient and reliable indication of where the DN of theblood pressure waveform is located.

In another example, the subject hardware can be used for determiningPressure Wave Velocity (PVW). In which case, the hardware will includeECG sensor contact or lead electrodes. To make the determination, an ECGand the heart sound is recorded at the location of the heart and thenECG is measured again while the Embedded Frequency (heart sound) isrecorded at a peripheral location (e.g., the carotid artery). Bymeasuring distance between the location of the heart and the location ofthe subject device and the time it takes for the Embedded Frequencysignal to travel from the heart to the selected peripheral locationartery (timing each off of the ECG signal which is travels through thebody instantaneously), then the speed at which the blood pressure wavetravelled can be mathematically determined.

In another example, the subject hardware can again be used fordetermining Pressure Wave Velocity (PVW). In which case, the hardwarewill include an external microphone. To make the PWV determination,first the heart sound is recorded at the location of the heart while,simultaneously, the Embedded Frequency (heart sound) is recorded at oneperipheral location (e.g., the carotid artery) using the subjecthardware. Then, the heart sound is recorded at the location of the heartwhile, simultaneously, the Embedded Frequency (heart sound) is recordedat a different one peripheral location (e.g., the femoral artery) usingthe subject hardware. By measuring the distance between the twoperipheral locations and the time it takes for the Embedded Frequencysignal to travel from the heart to the selected peripheral locations(timing each off of the heart sound recorded at the location of theheart), then the speed at which the blood pressure wave travelled can bemathematically determined to measure, for instance, carotid-femoral orcarotid-brachial pulse wave velocity. Alternatively, to measureascending or descending aortic pulse wave velocity, first the heartsound is recorded at the location of the heart while, simultaneously,the Embedded Frequency (heart sound) is recorded at one peripherallocation (e.g., the carotid, brachial, radial or femoral artery) usingthe subject hardware. By calculating the distance between the heart andthe peripheral location where the measurement is taken one canmathematically determine ascending or descending aortic pulse wavevelocity.

The subject hardware may also be used in connection with EmbeddedFrequency signal detection to provide a new approach to measuringsystolic time intervals. Systolic time intervals have been measuredusing ECG, phonocardiogram and arterial blood pressure waveforms. In thepast, three different devices at three different locations were used forthis purpose. Using Embedded Frequencies according to the teachingsherein, it is now possible to take measurements for calculating systolictime intervals with a single device and/or in a single location. In thesubject technique, the sound waves used in prior systolic time intervalcalculations (e.g., Circulation, 1968; 37, 150) are replaced by theEmbedded Frequencies measured. In which case, as indicated in FIG. 13C:

PEP=QS ₂−LVET  (1)

ICT=S ₁ S ₂−LVET  (2)

Q-1=QS ₂ S ₁ S ₂  (3)

where QS₂ is the total electromechanical systole, S₁S₂ is the heartsounds interval (in this case found by Embedded Frequency signalmeasurement), LVET is left ventricular ejection time, PEP is totalelectromechanical systole, Q-1 is the interval from onset of QRS to thefirst heart sound, and ICT is isovolumic contraction time.

In another example, Ejection Fraction is determined using PEP ascalculated above and the following equation adapted from Circulation,1970; 42: 457:

EF=1.125-1.25PEP/LVET  (4)

where EF is ejection fraction and the PEP and LVET parameters aredefined above. As such, EF is efficiently and accurately calculated on abasis including the subject Embedded Frequency signal acquisitionsystems and methods.

Variations

In addition to the embodiments that been disclosed in detail above,still more are possible within the classes described and the inventorsintend these to be encompassed within this Specification and claims.This disclosure is intended to be exemplary, and the claims are intendedto cover any modification or alternative which might be predictable to aperson having ordinary skill in the art.

Moreover, the various illustrative processes described in connectionwith the embodiments herein may be implemented or performed with ageneral purpose processor, a Digital Signal Processor (DSP), anApplication Specific Integrated Circuit (ASIC), a Field ProgrammableGate Array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. A generalpurpose processor may be a microprocessor, but in the alternative, theprocessor may be any conventional processor, controller,microcontroller, or state machine. The processor can be part of acomputer system that also has a user interface port that communicateswith a user interface, and which receives commands entered by a user,has at least one memory (e.g., hard drive or other comparable storage,and random access memory) that stores electronic information including aprogram that operates under control of the processor and withcommunication via the user interface port, and a video output thatproduces its output via any kind of video output format, e.g., VGA, DVI,HDMI, DisplayPort, or any other form.

A processor may also be implemented as a combination of computingdevices, e.g., a combination of a DSP and a microprocessor, a pluralityof microprocessors, one or more microprocessors in conjunction with aDSP core, or any other such configuration. These devices may also beused to select values for devices as described herein. The camera may bea digital camera of any type including those using CMOS, CCD or otherdigital image capture technology.

The steps of a method or algorithm described in connection with theembodiments disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in Random Access Memory (RAM), flashmemory, Read Only Memory (ROM), Electrically Programmable ROM (EPROM),Electrically Erasable Programmable ROM (EEPROM), registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An exemplary storage medium is coupled to the processor suchthat the processor can read information from, and write information to,the storage medium. In the alternative, the storage medium may beintegral to the processor. The processor and the storage medium mayreside in an ASIC. The ASIC may reside in a user terminal. In thealternative, the processor and the storage medium may reside as discretecomponents in a user terminal.

In one or more exemplary embodiments, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on, transmittedover or resulting analysis/calculation data output as one or moreinstructions, code or other information on a computer-readable medium.Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage media may be anyavailable non-transitory media that can be accessed by a computer. Byway of example, and not limitation, such computer-readable media cancomprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage,magnetic disk storage or other magnetic storage devices, or any othermedium that can be used to carry or store desired program code in theform of instructions or data structures and that can be accessed by acomputer. The memory storage can also be rotating magnetic hard diskdrives, optical disk drives, or flash memory based storage drives orother such solid state, magnetic, or optical storage devices. Disk anddisc, as used herein, includes compact disc (CD), laser disc, opticaldisc, digital versatile disc (DVD), floppy disk and Blu-ray disc wheredisks usually reproduce data magnetically, while discs reproduce dataoptically with lasers. Combinations of the above should also be includedwithin the scope of computer-readable media.

All embodiments disclosed herein are intended for use with memory,storage, and/or computer readable media that is non-transitory.Accordingly, to the extent that memory, storage, and/or computerreadable media are covered by one or more claims, then that memory,storage, and/or computer readable media is only non-transitory.

Operations as described herein can be carried out on or over a website.The website can be operated on a server computer or operated locally,e.g., by being downloaded to the client computer, or operated via aserver farm. The website can be accessed over a mobile phone or a PDA,or on any other client. The website can use HTML code in any form, e.g.,MHTML, or XML, and via any form such as cascading style sheets (“CSS”)or other.

Also, the inventors intend that only those claims which use the words“means for” are intended to be interpreted under 35 USC 112(f).Moreover, no limitations from the specification are intended to be readinto any claims, unless those limitations are expressly included in theclaims. The computers described herein may be any kind of computer,either general purpose, or some specific purpose computer such as aworkstation. The programs may be written in C, or Java, Brew or anyother programming language. The programs may be resident on a storagemedium, e.g., magnetic or optical, e.g. the computer hard drive, aremovable disk or media such as a memory stick or SD media, or otherremovable medium. The programs may also be run over a network, forexample, with a server or other machine sending signals to the localmachine, which allows the local machine to carry out the operationsdescribed herein.

Also, it is contemplated that any optional feature of the embodimentvariations described may be set forth and claimed independently, or incombination with any one or more of the features described herein.Reference to a singular item, includes the possibility that there is aplurality of the same items present. More specifically, as used hereinand in the appended claims, the singular forms “a,” “an,” “said,” and“the” include plural referents unless specifically stated otherwise. Inother words, use of the articles allow for “at least one” of the subjectitem in the description above as well as the claims below. It is furthernoted that the claims may be drafted to exclude any optional element. Assuch, this statement is intended to serve as antecedent basis for use ofsuch exclusive terminology as “solely,” “only” and the like inconnection with the recitation of claim elements, or use of a “negative”limitation.

Without the use of such exclusive terminology, the term “comprising” inthe claims shall allow for the inclusion of any additional elementirrespective of whether a given number of elements are enumerated in theclaim, or the addition of a feature could be regarded as transformingthe nature of an element set forth in the claims. Except as specificallydefined herein, all technical and scientific terms used herein are to begiven as broad a commonly understood meaning as possible whilemaintaining claim validity.

1. A system comprising: a vibration sensor adapted to capture avibrational signal including a hemodynamic waveform signal, and aplurality of electrocardiogram (ECG) electrodes, wherein the vibrationsensor and at least one ECG electrode are positioned on a distal face ofa device, and at least one ECG electrode is positioned remote from thedistal face of the device.
 2. The system of claim 1, wherein the atleast one ECG electrode posited remote from the distal face of thedevice is incorporated in a body connected by a cord to the device. 3.The system of claim 1, wherein the at least one ECG electrode positedremote from the distal face of the device is positioned on a handlesection of the device.
 4. The system of claim 3, wherein the devicefurther comprises a plug for an ECG electrode to be connected by a cord.5. The system of claim 4, wherein the device is adapted to deactivatethe at least one ECG electrode positioned on the handle section when thecord is connected.
 6. The system of claim 5, wherein the adaptation todeactivate the at least one ECG electrode positioned in the handle isprovided by a programmed computer processor.
 7. The system of claim 6,wherein the processor is housed in the device.
 8. The system of claim 1,wherein the vibration sensor is also adapted so that the vibrationalsignal includes an Embedded Frequency signal corresponding to heartsound.
 9. The system of claim 8, wherein the device is adapted toseparate the Embedded Frequency signal and the hemodynamic waveformsignal.
 10. The system of claim 9, wherein a digital filter is providedto separate the Embedded Frequency and the hemodynamic waveform signal.11. The system of claim 10, wherein the digital filter is provided by aprogrammed computer processor housed in the device.
 12. The system ofclaim 1, wherein the vibration sensor comprises a light source and alight sensor.
 13. The system of claim 12, wherein the vibration sensorfurther comprising a membrane, the membrane made of a material selectedto be at least partially reflective to the light source on an innersurface of the membrane.
 14. The system of claim 13, wherein themembrane comprises metal or is metalized on at least one surface. 15.The system of claim 12, wherein the membrane material is selected toreduce light passing from an outer surf ace of the membrane to thesensor.
 16. The system of claim 15, wherein the material substantiallyeliminates light passing from the outer surface.
 17. The system of claim15, wherein the membrane comprises metal or is metalized on at least onesurface.
 18. A method comprising: contacting skin of a subject at alocation peripheral to the subject's heart with a vibration sensor and afirst ECG electrode, both positioned on one face of a device, selectinga second ECG electrode from a finger electrode of the device and aplug-in electrode for the device and contacting the subject's skin at asecond location with the selected sensor contact, detecting avibrational signal with a vibration sensor, and detecting an ECG signalwith the ECG electrodes.
 19. The method of claim 18, wherein a user isthe subject and the selected ECG electrode lead is the finger lead, andthe selecting is by the subject holding the device.
 20. The method ofclaim 18, wherein a user is not the subject and the selected ECGelectrode is held by the user separate from the device. 21.-111.(canceled)